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mit-drl / e-vent

MIT Project: A low cost emergency ventilator controller
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bag coefficient documentation #65

Open synaption opened 4 years ago

synaption commented 4 years ago

If I understand correctly, there are 3 coefficients that determine the particular profile for different ambu bags but I could use a better explanations for each number so I can make things work with my ambu bag. These coefficients are in constants.h

// Bag Calibration for AMBU Adult bag const struct {float a, b, c;} COEFFS{1.29083271e-03, 4.72985182e-01, -7.35403067e+01};

amadoantonini commented 4 years ago

Yes, we should document this better. They are simply the polynomial coefficients of a second degree fit to volume-vs-ticks data for that particular bag. See here.

synaption commented 4 years ago

I had seen where they were being used, but I'm not sure how to change those numbers to fit my bag. Were the original numbers determined by measuring the volume change as the machine squeezed the bag?

amadoantonini commented 4 years ago

That's right! We'll add more documentation on that when we get a chance.

RubenPV591 commented 4 years ago

Hi, I've been working in a mathematical model for the Bag valve mask volume versus claw movement, I didn't knew where to share it in the group, so I'm publishing it here in case could be useful. If somebody knows if I should share this in another site just tell me please.

Greetings.

volumenAmbu02eng.pdf